How to make mat-checkbox unclickable in Angular material

This way it also becomes not focusable and you won't be able to check it using the keyboard.

    <mat-checkbox
        [checked]="state"
        [class.mat-checkbox-disabled]="false"
        disabled>
    </mat-checkbox>

use the disabled attribute

 <mat-checkbox [ngModel]="checkboxvalue" [disabled]="true"/>

or

<mat-checkbox [ngModel]="checkboxvalue" disabled/>

Refer Example

If I understand correctly, the user should never be able to toggle the checkbox manually. Instead it will be toggle programmatically depending on the input value.

You can very simply prevent the default click behavior, so nothing happens when the checkbox is clicked:

<mat-checkbox [checked]="infoBox.value !== ''"
              [disableRipple]="true"
              (click)="$event.preventDefault()">

  <input #infoBox matInput type="text">

</mat-checkbox>